In recent years, the display industry has been growing rapidly as new display technologies have been introduced to the market. Mobile devices, televisions, virtual reality (VR) headsets and other displays have been a constant force in driving displays to have higher resolutions and more accurate color reproductions. As new types of display panel modules and production methods are being deployed, surface defects have become harder to inspect using the conventional methods.
The above information disclosed in this Background section is only for enhancement of understanding of the invention, and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.